I had a similar problem last year on my Kioti RX 6010. The studs would break off just from the tractor sitting in one spot and not moved for days. The new factory same part number Kioti studs that I purchased were definitely different than the original studs on the tractor.
https://www.tractorbynet.com/forums...95-kioti-rx6010-lug-nut-studs.html?highlight=
https://www.tractorbynet.com/forums...95-kioti-rx6010-lug-nut-studs.html?highlight=